using Android phone I need read NDEF message (URI) from a microcontroller based NFC device. I read several standards like ISO/IEC 7816-4:2005, NFC Data Exchange Format (NDEF) and others. For now i have the following data exchange (crc bytes omitted when tx):
RX: 00 a4 04 00 07 d2 76 00 00 85 01 01 00 35 c0 // android selects file1
TX: 90 00
RX: 00 a4 00 0c 02 e1 03 d2 af //android selects file2
TX: 90 00
RX: 00 b0 00 00 0f 8e a6
TX: 00 01 02 03 04 05 06 07 08 09 //it is the dummy data
//here android restarts autocollision detection process
Maybe somebody can explain me the workflow of the commands. I dont know what file id means (file1= "d2 76 00 00 85 01 01" and file2= "e1 03")
I stopped at the first READ_BINARY command. i dont know what to send in response and where to read about this. I supposed that i need somehow insert the NDEF payload here. Also here another nfc topic i found that the response to the first BO should be so called "capability container" but i dont know what is it, and it is not said in the NDEF specification.
The NFC spec for Type 4 cards is a good read
"d2 76 00 00 85 01 01" is the AID (Application ID) used for NDEF
"e1 03" is the Capability Container File ID
A summary of NDEF reading from a Type 4 card is:-
Capability Container File contains things like the File ID of the NDEF file, NDEF version number, NDEF read/write security, Maximum NDEF size,Maximum read sizes, etc.
All defined in the link of the NDEF spec I gave.